Lest you think all morality is subject to popular opinion, Pope Francis has published his first papal encyclical in which he reaffirms the sanctity of marriage between one man and one woman.

The encyclical, a collaboration between Francis and former Pope Benedict, makes clear that the Catholic Church is not going to surrender to fashionable opinions despite the growth of the homosexual marriage movement.

That’s bad news for homosexual activists in the U.S., who were just handed the right to a whole slate of government benefits by the Supreme Court.

“The first setting in which faith enlightens the human city is the family,” Francis writes. “I think first and foremost of the stable union of man and woman in marriage. This union is born of their love, as a sign and presence of God’s own love, and of the acknowledgement and acceptance of the goodness of sexual differentiation, whereby spouses can become one flesh and are enabled to give birth to a new life.”

The main argument for homosexual marriage has always been an appeal to social pressure — go along or be bullied and ostracized.

The pope stands up to this sort of moral myopia in the encyclical, looking back to the Old Testament for the roots of Christianity and criticizing the idea that “truth is what works and what makes life easier and more comfortable.”

Francis points out that truth and love come from surrendering to God’s plan for humans, not from our own selfish desires.

“Promising love for ever is possible when we perceive a plan bigger than our own ideas and undertakings, a plan which sustains us and enables us to surrender our future entirely to the one we love.”

The pope’s message of tradition and the constancy of morality is one the world sorely needs today.